Natural selection and cultural selection in the evolution of communication

Kenny Smith

Language is transmitted from language user to language user. Much debate in linguistics centers around the nature of this transmission. Under the traditional Chomskyan framework language transmission consists of two components:

1. Genetic transmission of a genetically encoded language acquisition device
2. Cultural transmission, via parameter-setting learning, of particular languages which are parasitic on the innate LAD.

A growing body of work, both theoretical and computational, considers the possible roles of genetic transmission and cultural transmission in the evolution of communication.

Genetic transmission is typically non-random - genes may have characteristics which increase their probability of being transmitted into the next generation. For example, a gene for faster running in gazelles may be more likely to be transmitted because gazelles bearing the gene may be less likely to be eaten before they have the opportunity to breed and pass on the gene. This process of non-random genetic transmission is known as natural selection.

Similarly, cultural transmission may be non-random - certain culturally transmitted systems may have characteristics which increase their probability of being culturally transmitted. For example, cultural systems which are easy to learn may be more likely to be successfully transmitted simply because they are easier to learn. This process of non-random cultural transmission can be termed cultural selection.

This presentation concerns the roles of natural selection and cultural selection in the evolution of simple communication systems. Their interactions are studied with the aid of a computational model of the evolution of communication in a simulated population. Cultural selection, rather than natural selection, proves to be the determining factor in the development of communication in the simulated populations.